SSRIs include such widely used antidepressants as Celexa, Paxil, Prozac and Zoloft.

The authors, from the World Health Organization and the University of Verona in Italy, conducted the review in order to assess whether SSRIs reduced or increased the risk of suicide in depressed people.

Some previous research, including a 2007 U.S. Food and Drug Administration study, concluded that the SSRI-related risk of suicide was neutral in adults, elevated in patients under 25, and reduced in people older than 65. In response to those findings, all antidepressants now include a black box warning regarding increased risk of suicidal symptoms in patients younger than 25.

"While the FDA found a neutral effect of SSRIs (or a promoting effect in adults aged 18-25), we found a strong protective effect associated with SSRI treatment in adults," wrote Dr. Corrado Barbui and colleagues.

The researchers concluded that "data from observational studies should reassure doctors that prescribing serotonin reuptake inhibitors in patients with major depression is safe," but children and adolescents taking the drugs should be closely monitored due to the possibility of suicidal thoughts and attempts.

The findings were published in the Canadian Medical Association Journal.

In a related commentary, two American experts called for randomized trials to determine the safety and efficacy of depression treatments for young adults. Such studies would help guide doctors, who have become extremely cautious when treating this group of patients.

Dr. John Mann of Columbia University and Dr. Robert Gibbons of the University of Illinois, said it's alarming that "concerns about the risk of suicide in youth have led not only to fewer SSRI prescriptions without substitution of alternative medications or psychotherapies, but also to a decrease in predicted rates of diagnosis of mood disorders."

More information

The U.S. National Institute of Mental Health has more about depression.